Crossing signal



Dec. 6, 1932. 1 M. D. WILSON 1,890,352

CROSSING SIGNAL Filed March 11, 1931 2 Sheets-Sheet l Jay;

Inventor Mercer D. ll/i lson.

Jlttorney.

Dec. 6, 1932. M. 0. WILSON 1,890,352

cnossme SIGNAL Filed llarch 11, 1931 2 Sheets-Sheet 2 I nuentor PatentedDec. 6, 1932 l V ivrnncnn Wilson,- or PHOENIX: ARIZONA, ASSIGNOR ifo ,s'rANnARn cnossrne; GATE ooRroiaA'rIon, or rnonnrx marzonn, A'conronn'r ron b'r nn zonn "i j cnossme SIGNAL" Applicationfiled March ;f11, 1931; SerialqN o. $21,685:, 7

v r j This invention relates to traflic control de- "YICQS, particularly to automatic signaljmechanisms that are responsiyefto a passing velllClG SHCll a tramor electric car; My' nvention may be readily adapted to the solution :ofavarious' problems in traficcontrol, bllt'lS particularlyapplicableto trafiic control at an intersection where it isj-desired'that one lane, forinstance an automobile 1 highway, be blocked off during the approachand passing of a vehicle in a second intersecting lane, such as a train moving-along a railroad track. "Hereinafter the lane controlled by'the signal member will be referred to as the traflici .lane,' and the vehicle in the intersecting lane to Whichthe signal mechanism isresponsive will be termed the control vehicle;

piace the parts intheirgot My invention includes pivoted signal 'means'which may be adapted to swing either tvertlcally or horizontallyias a purely vlsual signal, but which preferably swings in alionzontalplane to serve-as a traffic gate." This signal means reciprocates between a stop osition'and a 'o osition one movement Z3 of the reciprocation being" effected" by, a

power-driven mechanism and the opposite movement of the reciprocation being accomplishe'd by the force of grarity. Bythis arrangement, the power driven movement'not only moves the signal memberfrom one pcs1- htionto another, but alsoby displacing asuitable Weight against the force of gravity stores energy in the form of energy of 13051111011 tobe used inaccomplishing the second andoppo- "site movement of the signal member. Prefers ably, the signal member indicates go when it isat thevend of the power-driven movemcnt5 energy being then stored for the opposite movement of the signal member to the stop position. L111: other Words, when theslgnal s in its position indicating go potenv tial energy is available for the second movement, anden approaching vehicle controlling the signal mechanism merely serves to release the stored energy. After the: departure of gthe vehicle the power-driven movement is autonraticaily-initiated and completed to positions. An important advantage" of this arrange- ;mentisthat in casethe power-driven mecha- -nism fails"hilfunctionthe signal iii ember move to theistop positionat the' approach of the first controljvehicle, and then Will fail {to move from the stop positiompthereby "calling attentionto the condition of the mech- 11ialis=maintainedin thefgo position only'so long as anelectrlc control circult s 'energ zed.

A con'tro'lvehicle; by tie-energizing this cir- ,cuit, initiates the gravity-moveme-nt.of-thel V mechanism. Consequently, When-the control circuit is opened or otherwise dc-energized foriany reasomsuch as by accident or because ,of a defect, the signal member immedlately moves to tlle istopi position.

;- -Inorde'rto avoidfdamagein casea'vehicle I in the trafiic lane shouldicollidewith thepivoted signal member, my invention provides for yieldingly mounting this member. Preferablyithis isaccomplishedby incorporating i v a floating sleeve embracing-a verticalshaft shaft engaging :a Vshaped cam surface on fromeny egree of rotary displacement- A The ;.po vv er-driven in the m and supportedthereon by afollovveronthe I I v the vsleeve. In'my preferred formz' of: this 3 V I'flexible connection, thesignal member will return to, its proper. position automatically 1 ferred form ofjmy invention incorporates a fluidpressure-actuated" mechanism, preferably in the formof ahydrauliclift actuated by anjelectrically driven liquid pump. 1 The use of a hydraulic lift results in anreven movement of the signal member, thereby;

- minimizing shock on the moving parts ofthe i mech anism. A: feature of my preferred modification is that on the gravitymovement .of the devicev the lift serves as a hydraulic V cushion. Iprovide by a combination oftwo'switches in the motor-circuit, one a mechanically actuated 61 o tr lling the sal ne lift switch normally held open against the 210- f tion of a yielding'meansthe seconda relay CUitptO, beheld closed inry oppositionitofits switchcnormally energizedbythe-controlcir tro'l circuit is de-energizedby theapproach of I a control vehicle, the relay'switch opens and 7 l the mechanical switch release'dby the gravity 'movement of" the mechanism thereupon closes, The motor is idle untilthe control circuit becomes energized upon the depar- 'ture of the control 'veh-icle,' thereby closing the relay switch. As the moving *parts reach their set positions, thelmechanical switchis forced open to de-energizea the motor circuit.

Thisv inter-relation of the two switches provides forautomatic control of the motor. I

The mechanism is'sustained in itsset position' against the force of gravity by fluid pressure within the hydraulic lift andthe gravity movement fromthe :set' position is provided 7 it a by releasing saidfluid pressure, For this pur:

pose a valve in a relief pipe communicating with the pressurecylinder of fthe ram is weighted to: gravitate to anopenposition and normally heldclosed against-such gravitation by virtue of a solenoid energized by the 7 g "The solenoid has" sufiicient power notonly to hold theivalve closedbut' 7 control circuit;

' also; to move it I to' its weight from the 'openfpos'ition in plete automatic control ofv the signal member.

tages of my improvement will'be apparent i in the detaileddescription 'to' f ollowl. consid-v fered with the accompanying drawings, in

which f Fig. l is aside .elevation of myinvention;

Fig; 2s an enlarged side elevati'onfpartly "in'secti'on showing the part at the beginning "nism areenclosed byig-a housingcgenerally 5 f the'po-wer driven movement;

*iatfifiqeh t th ow r-dr e m ment; in, th'eirfnormal positions; i

' 7' Fig. I4: is it horizontal Fig. 3'is a similar view'show I V section taken asfindi cated'b'y' the lines of Fig. 2; l Fig fis'a lateral vertical cross-section of 'thesignal'member 'takenasfindicatedbythe line 5=''5 of Fig. 2"; and

f 6 is a wiring di gram suitable preferred formofmy invention.

The -working parts" of the signal'lmechadesignated '20, which comprises agcylindria cal wall 21, atop plate 22a; and it bottom'plate 22?). Through top' plate 22 ao-ver ti calshaft V 23 ex'tends to serve as ap v'otal mounting for the signal member; which isgenerally designated by the numeral 24. The signal mlems ber'is flexibly connected to shaft23' by 'virtue f 'a floating sleeve 25, which carries-the sigi friction roller 26 radially mounted on the Perinherjv of-shaft 23..

1191 member, and which rests upon a non:

The-lower edge of sleeve is to 1 I a V sha'ped recessor cam surface forming a vertexi t 125a and oint '7 512559 5. The

- relatively long arm Theabove and-otherobjects andfadvan-f new i roller 26, mounted radially on shaft123,;supv ports the sleeve by normally engaging vertexva. The angularity of thecam' surfaces andlf V the magnitude of the superimposed weight is such that the normal relationof vthejslefleve land roller is maintained duringordinary.

movements of thefmecha'nismand tends-to be restoredwhenever an-eXternal force or obstacle causes 'thesleevelto rotate relatlve'to Vtheisha ft ,7 r 7 a a Signal memb'er24'prefe rably,comprises; a 1

28- serving as a crossing 7 gate anda relativelyshort arm '29; serving j to counterrbalance the long arm. Each arm' I j v 80' Y jlight frame members or'bars'BO whichareat 'tached to the sleeve 25 at theirinner(ends comprises" a pair, of horizontally disposed and converge together at their 'outerends;

The outer ends of the longarin andthe short arm are supported. respectively by cable er and-32 which areflconnected to the; top of 1 sleeve25. "As additional support for 'longer arm 28 an additional-cable 33 extends from the outer endrof thefarm to a "collar 34PM- tached to-sleeve 25,and at spaced intermedi ate points; along this cable s'addles35 are hung and terminally connected to bars' BO,

as shown in Fig. 2. At the outerendi'of the h shorter arm 29, a weight 36 servestocounter- I balance the heavier: arm 28 and a suitably dimensioned vane'37 serves to e'qualizesur V faces presented to the wind by'thetwo arms; T y

Shaft 23'isfvertical'ly aligned to floaton'a a thrust bearing; generally designated} 38, and which is supportedzby aj horizontal plate 39.

Plate39 i's attached at each end to cylindrical Preferably a' feltcollar l8, retained by collar theweather askirt49 carried by sleeve 25 may extend over the bearing.

, It is essential that bearings 44 not only pro videfor the vertical alignment of shaft235: but also freely permit vertical movement of sleeve 25 when thesleeveis rotated relatively Tto theshaft 23. f i 7 1 'wall 21 of: the housing; #This 'thru'stjbe'aring j 'may 'be of a Well-known type comprising-a cup me mber 40; presenting a'spherical surface, andtwo rings 41 and 42 forminga' race for steel balls143, the lower ring 41 seating in cup. member lOandthe upper ring 142 abutting a shoulder 230 on the shaft. j flVert-i'cal alignment of shaft' 23 maybe maintained by a radial bearing agenerally" designated 44 mounted oniupper plate 220:. aThis bearing may be designed as indicated in the drawingsiwherekfi is a ring forming a race retaining steel balls i6 in'contact with the peripheral surface of sleeve '25 and 47f designates a collar for v securingv ring 45.

.47, iservesas adust ring; For protectionfrom I end againstrotation around shaft 23 by means of vertical guide rods .52 which arereceive vertical bolts 51a carried by weight 51. I

Weight 51 is operatively connectedto shaft 23 in such a manner that vertical movement of weight 51 from the position shown in Fig.

2 to thatshown in Fig. 3 causes shaft 23 to rotate approximately ninety degrees in one direction, and the reverse movement of weight 51 causes the reverse rotation of shaft 23. Preferably this operative'connection is provided by means; of a radially inwardly extending non-friction roller 55 carried by the inner peripheral Wall of sleeve engaging a spiral-shaped groove 56 cut in the periphery of shaft 23. In the preferred form of my invention shown in the drawings there are two of the inwardly extending members diametrically opposed and two corresponding grooves 56. Rollers. 55 serve as followers engaging cam surfaces presented by grooves 5'6,'the cam'surfaces 58 being engaged on the. upward movement of the weight to revolve shaft 23 counter-clockwise,ninety degrees, and cam surfaces 59 being engaged on the downward movement to reverse the rotation of shaft 23 by ninety degrees. Preferably the upper'and lower ends of grooves" 56' are extended vertically so that minor movements of'weight 51 at the upper and lower limits of its range of movement will not revolve the shaft beyond the desired ninety degrees. The mass of weight 51 is 1 such that by theforce of gravity alone it will move freely. if unsupported, from the set position'at the upper end of slot 56, shown in Fig. 3, to the normal position shownin Fig. 2, revolving shaft 23 during such movement.

The power means for moving weight 51 up-.

ward preferably includes a'hydraulic. lift,

' generally designated L in thedrawings, comprising a cylinder C having a piston P, from which two spaced piston rods 60 extendup- 1 ward and terminally connect with a yoke 61.

Yoke '61 has an integral collar 62 slidingly embracing shaft 23 and carries .in brackets 63 on its upper surface non-friction rollers 6d positioned to abut the lower face 65 of weight 51. "By meansof these rollers vertical force is transmitted from the lift L to weight 51 with a minimum tendency that lateral vibrations of the weight may be in turn trans mitted to piston rods 60. Yoke 61 has an off set extension66 from the endof which de- ..system, t p Tank is internally spanned atan intermediate horizontal plane by av plate -7 5. suit.-

pendsa vertical rod 67 slidinglyjournaledin aperture 39a of plate 39. The lower end of rod 67 is screw-threaded torecei've an adjustable nut 68 having aradial set-screw 6.9. Nut

68 cooperates with an automatic switch Sin a manner to be later described. Hydraulic lift L maybe constructed to include a closedtank, generally designated-70, the lower portion of which .is the working cylinder-C, an upper portion 72 serving assa'.

liquid reservoir. Reservoir72 and. working cylinder C are connected by. a pipe 73 to feed-' the working t cylinder and a returnflpipe. 74,.

a self-containedhydraulic thus constituting ably apertured at 7 6 topermit the free fiow of liquid therethrough. The spaced piston" rods 60 are preferably guided in their' lon-u i gitudinal movements by suitable apertures 77 plate 39, apertures 7 8 inthe upper head 79 of tank 70, and apertures8O in -plate 7'5. i

The lower ends of piston rods 60 are received by the piston P and suitably secured theretoas by means of opposed nuts 82 and 83 screw-threadedly engagingathe piston rods. Piston P, having fluid-tightffit with the in ner peripheral surface 84 of workingcylinder 71 and. being adaptedtoreciprocateiven tically in the cylinder, is of a type well-known to the art. It has'a lowerworkingface85 and is bored to form a relief passa e 86 c0ntrolled by an .automatic'reli-ef valve 87. i

This valve includes a valve stem 88 proj'ectingupward. throughithe passage. The stem carries on its low'er-end a' bevelfled "closure plate89 and on its upper end a header flange 90'. Ahelical expansible spring91 surrounding the upper portion of the stem is a confined between the upper face of the piston and flange 90, thereby continuously exerting a force tending to seat closuiy'e plate 89in a complementary bevelledvalveseat 92 formed at the lower end ofthej relief passage. Valve 87 is so positioned that it may be opened at the upper end of the piston stroke by the impingement of valve head 90 against plate 75, thereby reducing the liquid pressure on the The relief 5 valve serves as one mea-nstolimit the upward working face 85 of the piston.

movement of the piston.

Incorporated infeed pipe is a fluid". 3

pumping means, prefe'rably-a'gear pump 93,- arranged to propel fluid under pressure into f cylinder C. A check'valve 9 1 in feed pipe below pump 93 prevents flowfin :the opp'osite direction from the cylinder towards the" pump. Pump 93 is actuated by a "prime mover preferably in the ,formf'of an electric motor 95 5 operatively by a shaft.,,96. a

The circuitenergizing this motor may be automatically controlledy by a mechanical switch S and a'relay f SWitch S" includes connected to the pump ECU Z the opposite tendency of weight-108 and upon two contacts :97 and 98 mounted on the bottom of and suitably insulated from plate'39. To. contact. 97 aswitch-blade 99Vis pivotally mounted the .end; of the. blade disposed tospringlOL: Spring 101 tends continuously to close the switch. Switch-blade 10,07 is extended to the other side of its pivot-point as an angular. bifurcated I conducting material. The forked 7 ends of arm 102 also of nonarm'102 extend-on each side ofrod 67 and are 'positioned tdbe engaged by nut68thereon.

' de-energize motor 95.

' Nut 68 maybe adjustedito coact with arm 102' atPa' suitablepoint to terminate the power stroke of piston z=81 by'opening switch S to v I wire118 interconnecting the second. terminal of the solenoid coil-and arr-intermediate 'cellqg5 tln the'set position of .theparts, as shown inFig. .3, switch' S- is heldopen by nut' 68. Whenever the moving parts retract from.

their set:- positions, spring "-101 closes the switch, as shown in Fig. 21* Preferably automatic switch S, rather than relief valve 87,

is adjusted tostop theupward movement of the ram, the relief valve serving as an emergency device becoming effective to limitt upward movementof the piston only when,

inertia causes excessive movement of the pump afterithe motor is de-energized or in icasepswitclr S fails to. o en,

RelayR in the-motor circult is actuated by a normally. energized control circuit which is 7 adapted to bade-energized by the. approach .iliary against the worlzing'face85 of piston P.

1 Automatic control of valve 104 may be attained by mountinga suitablesolenoid 105 yon the lower face of plate 39 and electrically connecting it with the aforementioned control circuit. From a core 106 depending verof aicontrol vehicle; The relay is designed to havejan inherent tendencyto open'and. is closed only when energized by the control cir- "cuit.

At the lower end' of return pipe 7 riseror stand-pipe 103 may branch 'ofi' vertically to serve as an air cushion,-the upper end being sealed. Above the openingof "this -p'ipe, means maybe provided in the-form of a'val've 104 to control flow through returnfpipe 74. 1 By arranging an automatic control to' manipulate; valve 104, I provide means auxto pump 93 for controlling pressure tically fronisolenoid 105, a chain 107 is sus- 71 Q pended to carry a weight 108, and at an in i termediate point on the chain a ring 109slidi inglyengages handle 110 of valve 104. .In

the set position of the mechanism shown in "Fig. 3 thefisolenoid being energized-by the 0 control circuit, holds valve 110 closed against de energization of the solenoid,,weight 108 upper straight portion of slot 56. c

When acontrol vehicle enters a control zone defined by the length of insulated rail section 116,'the controlvehic'le short circuits the control circuitas indicated'bydotted line' 121 inFig. 6, thereby de-en'ergizijng relayfR flIlCl solenoid10-5. jlVeight 108iminediately opens valve 104 to permit the escape of fluid from"cylinder G and piston? yielding to weight 51 .drops smoothly'to the position I shoWninFig'Q. short interval aftenre lay-R opens a gap in wire 112, switchS'is released .by the downward movement of the since in additionto operating the valvefen ergization .ofthe ,solenoid mustliftthei weight." Y he The Wiring of myinvention may be under;- stood-from Fig. 6, indicating my preferred arrangement. Fromv a'suitable source of current, such as a battery 111, leads 112 andj113 and the relay, wire 114. extends to the coil "of 7 relay Rand is connectedaby a branch wire 115' to an isolated and insulated section of rail 116. NVire 117 interconnects terminals of'the'coils ofrelay R'and solenoid 105, and V v in battery 111' completes the control circuit.

lVire 118 has a branch 119 connected to the second rail 120'. 1

1 The automatic operation of 'myei-nvention' may now be reviewed,"starting with themecha'nisrn inthe set position shown inFig.-3.

Valve 104 is held closed bysolenoid105, relay j R is closing a gap'in wire112, switch S is open and the motor is idle with pistonlE, at the piston and closes wire113,1but because-of relayiR being open themotor is not energized. I 'S gnal'arm' 28 1s swung across to block' the 7 traffic lane aslong as the control vehicle re 1 mains in the control zone.

The same sequence of movements would "top of its stroke.- If fluid leakage should develop, switch S will be released to energize} 4 0 motor 95 before follower 55v drops from the result from'failure of the controlcirc'uit for 7 any reason, and obviously failure. in the -mozone, the control circuit returns to its normal tor circuit would prevent; the returnoffthe signal arm to its normal position. g

state,.energizing relay R and solenoid 105, V

'ivith. the result that solenoid 105 closesvalve 104 and relay R closes to complete the motor circuit. The motor drivingpump 93 immediagainst cam surface58, signal arm'28'is re} turned to its normal position. I .When the follower enters the upward straight'portion-of.

1251 'ately builds up pressure in cylinderl c forc I lngPiStOIl P upward, As follower 55 acts lot 6, 1 11 8: ope s i h s, g zin was 9- f wlt h S fai "Q @1088 f er" ny o h rr aso fl d 'r r ssur nti u to be built up in cylinder ,-re1ief v lvesfimg -pi e snpehpl 1hip even d eei l Pis fn, n sl hh Ca e, l jh d at h o? iIitS t qke with the flow from the pump] i g h rried. hr ugh relief passag 86 nd} an apertur 76" o' res vhi 7 F F r he p rp (i is l 's n I ha e .e hrih d a p ete m-d rm n specifi l; bu t ste e co zed t -1 N enti x may h e yl mo fied withbet changing its essential character and I reserve;

h ght to. all such modifieations that are p qp y .vithih he range [of my. append d? claims.

t-ivel V member mhuh ed. ax l y slid' b ela ive to the shaft; am mean i e e h ng Sa d shaft an l d hle m mber reby mo eme t of said member will ce se'rotatioi of the ha P-Q'W r e s o raise sli ble h ainst rav ty d 9 .1 56 t t on 0f he she-ft in one direction; said; slidable'i nember being s i ficiently weightedto cause rotation of theshaft in the opposite direction by ts.

gravitational fall; and T631953 control controlling the povver 'hieens,

. s he sys a signal member; a revolvable shaft-opere'jj tively conneeted with the signal member; a; member mounted axially slidable 'rel vetive'to the. shafmcam means interconnecting said shaft and slitlable member whereby moveen o s dm ber i l m emta io f t a pe r me ns to ai e h l da le; member against gravity and cause rotation of the shaft one directiomsaid slidable rnexnf' h being su cien ly We ghted to cause otation of hesh ft in the! epp i rec e hy i g i o al all; and me n sp ns ve to a passing vehicle to control 'thej povve'ii means. A

A nal ystemhavm ,in biiee n ign m m e r el l S f pera t e co t d t thes gn limem e i-i ela ive th haf nd, hav ng qp t v I connections with the shaft whereby the shaft,

weig- 't adapted for; non rot'zttive movement is r vclved by u h mo em n oi, t e e gh p we -ac e m an ad p d ttq moveiithe Weight gai st gra ty, t er y ing the sh ft ne direction, the Weight b in adap o' ke t e everseim e t by av y, eby revo in he f i t e opposite direction andmea is responsive to ated mems. 4- hs gh sys em hav ngfih com i n:

a passingvehicle to control the power ecti s e S gna member; a revel abl sh op re- 'lhistrat hg h inQ P es-ihcQrP mte -m my ice Having se ihed my i YQI 'Qi i ;,I l im v e l.- A sig al sy em h ingn combihet a s gna m m er e elvfi le hah opera-f CQnnected with thei gl al vmflmb ii; i

having, in combinatioii zf tivel "connectefi gto, thefsi gn l fi l b l' 84 I Weig t adaptedj forrigtfirotitivejmoveme lfi relative to theshaft and having operative h ee ee ie e ith the hhft' vhe' he She t 1s? e qlved by suc 'mov mentof 6 w ight v i v k v '70 pre l h thetedlij e edwmetel the-t1 ig fegeihs t g av t h re yr ve vin lf H r he' helft: i ne d r c -W he Weigh be ng t adep jd t make the reve s m ment, by

by e el-hing t e sha t 1 h hv yz' h 'i pp site direeti'on; viewe means to; deli er u d nde pr ssu e thefln d pre sult it;

h ylhe iinethel if in ne di e nhhd' I18 p n ive tea, passihgveh th ee le se the fluid in thglift;

5 A ig syhtm. ha i g, h'e bin t oh a sig al member; m vel hh e the p im ive y' nne t d t he nal ,im mh'e 1 Weight edapt'ed for non-rotative movement:

tivew he h t n ha ng pe fi ve fwl r iti nS w th t e ehef whe e y e sh t s revolved by' siichg'movement of; the Weight;

flu d P ess re hhleted'lift pte to move he ei ht ai t ra ty fl e r l'vin the shaft i h dire ion, the ht e ng adapted to mak the reverse movement-by.

gravity,v thereby revolving the shaft in the hfeliiii r l tive'to t ehz s of e s a 5 movable Weight" confined, to nonerotetiv'e movement relative .toithe shaft; a follower associated ththe. weig nd ga ing s i'i cam surfaces to i rotate the shaft; povver act-ul ed m ans ade'i ted tdmdv we g t a iliht gravityfiher by revolving the shaft.

WQY di cti m, t w i t bei g adapted t ake h e rse m e en by g a ty fively "connected to [the s ig alinember, said ha t having am surfaj e 'ph 'p e' y in lined ife a i t he hx f he h t; wel ghtfconfined to non-rotative' movement relative to the shaft .1 2 1; follower associated fish sfg d 'l e y re vi he shah? in one d rection; the :Wcightbeihgadapted to.

on -dimetiohhgei stthe we ght; an m ns 25' make t h revers m vement by gr v y; thereby: r elvin th shaftinme opposite direfiiii l means to deliver fluid npres;

Sure with? fi thereby me h th l ti 130' 7 thereby revolvingithesheft'in thelopposite I etih ndm hn mmn oh m ihg i vehicletopontrd the povverectuetedfineahsl 4 A. ig a syt'em having, i Co ination h h-al'memh hi e revdlveb sha op -1 izo j hve gh d e eg se d c msur- I aces to rotate. the shaft}, 34 fluidepressUrea :Asignal systemi'having', inieoiribiriatiorif:

a Signal member a "fev'olvehle shaft operatively Connected tof the'fsignel me ber; s a .e Tvveig'htf adapted for noiiirot'ative' movement relftitivelto the shaft andfhaving operative'f :ida'pted to make the revers'efmov'eiherit grzivityyt'hereby' revolving the shaftin'jthe Opposite, direction; adp lmp operetively com nected'vvith said lift and' a'dapted'gtodeliver, I I h gr'avitatijonal movement of theplston. r

fliiid ,to the lift under pressure; a; motor-op-v eretive'ly connected with fsaidjp lmp; a n au t OlIliil'ilc switch in the motor cirei itas'sociated With the lliftja'nd adahted to deel ergiz'ethe V niotorgat the end ofthe lift movement against 7 the weight; at second ;auto m'etie 'swit'ch re e spon'sive to 'a Control vehicle" to energize" the ;upon the approaehofithecohtrol vehicle,

*z'r' signal niei'nber; erevolvable shaft op'eraif-sha-ft'having cam' surfaeesjon ts-"peripheryi m tQlf'upo i the rdepart'ure'r-of'the reontriol vehiele"; and means responsive t0 "the (:o'ritrol vehicle to release the fluid pressure 'inthe lift 9Q A' 'signal systemhaving', iri coi'nbina'tioni :tively' connected to thj'fs'ignal member, said inclined" relative .to thegai;i s' of the; shaft; 'a "weightconfined to jrien-rot'etivef {movement actuated lift ada pted l toi move the vWeight e relative to the; sheft I a follower; 'zissocieted with the" Weight and: engaging said leairiJsiir faeesfito rotate the shift; I a jfiuid-pr'essure- :igainst gravity," thereby revolving the shaft in one direction' ftheWeight being adapted to make thereverse movement by;gravity,

7' "thereby revolving the shtiftin the, Op osite direction; etpump operatively connected with said Ilift and ada'ptedfto deliver fluidiihder pressure thereto; 'zf'jhotor op'eratively ;oon- I Ii'ected' With saidi'pliihp h an automatic f'sW'it-h the motor I circuit:assoeiatd v vith the lift and a'daptedto opeii'fet the endof-the lift V movemeiitfagainstthe weightfe second an 5 v. 'i toiriatic switch responsive tdfa control vehicle I the cor tr'ol vehicle; eridfmeans responsive to energizeithe motor iipon? the depart-1nre of I to the control vehicle threleasethe .fluidepres- 10; A signal system" havihg5' irfieoiiihiiia shaftlbysuch movement; a pressure cylinder; la piston operatively" associated 5 with "the Weightarid adapted" to recip rocate exigilly within the eylinder, Iiioving inonedi'r'ectiofi' by fll lid Pressure against'the- Weight eridin ton under pressure; a check 'valve infsafd P p p 'we'r m'ee sfl a ua vthe Ip mp;

autqmatio means associated With said piston;- 1 and adapted tode iiergizejthevpovverr meai sf r to the control vehicle to reduce thefiiiidpres'j j v are r tothe signal membere weightd sl ve slid shaft in one j directioh and liiiea-r movemeht' of'th'e Weight in the'jopposite direction p o:

make the reverse moveme"rit'byi gravity, and j ht; alp m'p; pip o n he-P mp and cylinder, "s propel fl iid to the e pump being adapted to;

Hider againstthe is-j movemeiiti-of' the piston; a' see'ohd eutoirietig means responsive to g; eor trol'vehicle, t d 51 1 ergize the powerhje'ains, u'p'onTthe departlire' ofthejcoritrolv'ehiole and means responsive 's iire against said pistOh pdn}thejepproaeh' o h the, "control le, 1 there yle'ausing the ."llfA signalsy'stem, havin'g, in combine i ni s 'alf i b ;aes b t nfiielly ve t l ingly embracingthe fjsl ftian'd fadlaipted tof,

reciprocate thereO Q eKguide enggigingfthe j I sleeve and adapte d tofjeofifinethesleeve to i e .mev nt:fparalr li ith the h r rca'mgand fonower eonnetion fbetiveen the vv'eighted sleeve and shaft vvhere'hyi -liriea r s t n d int rOta't mov m nt. 5f the/1 'duee's't he opposite rotative effectgipovver c:-

against grejvitfy, the Weight being 'atdapted to we e ea 'futo atic'l ea ns esponsive to hieletoeoritrolthelpovverhieerrsi" I 1' 12. signal "system having, in combinetioii: a signal member; a substantially verti cal, revolvableshaft" operatively- Connected 101" to the signal member a fvve'ighted sleeve slid 7 i y; rac sh f I we l p iw reciprocate" thereon it" gii'idel engagin the linear'moveinent parellelwiththe shaft; a 11(- mn llowr conn c n bel veeifi h 1 r 4 1 weighted sleeve and 'shaft fwhereby liriezir sleeve and; adapted to'lcorifir 'e the sleeve to r n l td btafiiv mo m nto e shaft in; 19" direction end flineer r i ovement of the weight ir fthe opposite direetio i p'r dupes theiopposite rot'dtive effect a' fluid? 'pressur t t l ft edap edi't mere he" f i t" aga ns g ar inkthelri ht be ng adapted tom-eke thereversenioveineiitiby gravity ;p' ei m i ij del v i H d lend i j pressure to the lift; thereby" ;m ovirigi the-lift j in one direction autoiiiatic 'irleei 's' responsive e fluid pressure ilrthe' lift, thereby j the weight to retractithelift 3- AT" S gne y m i Y gili iff fib a 'tioIi a signal member sub'smnti-euy;verti 13 cal, revolvable shaft operatively connected the signal member; a weighted sleeve slidingly embracing the shaft and adaptedto reciprocate' thereon; a guide engaging the weighted sleeve and shaft whereby linear movement of the weight in one direction is translated into rotative movement of thellnear movement of the weight in one direcshaftin one direction and linear movement of the weight in the opposite direction produces the opposite rotative effect; a iiuidpressure-actuated lift adapted to movcthe weight against gravity, the weight being adapted to make the reverse movement by gravity; a pump operatively connected with said lift and adapted to deliver fluid under pressure to said lift; a motor operatively con- I nectcd with said pump; an automatic switch associated with the lift and adapted to deenergizethe motor to terminate movement of the lift against the weight; a second auto-c matic switch responsive to a control vehicle to energize the motor upon the departure of the control vehicle; and means responsive to a passing vehicle to release the fluid pressure within the lift, thereby causing the lift to re,- tract under the weight of said sleeve,

14. A signal system having; in combination: a signal member; a substantially vertical, revolvable shaft o-peratively connected to the signal member; a weighted sleeve sliding- 1y embracing the shaft andadaptcd to reciprocate thereon; a guide engaging the sleeve and adapted to confine the sleeve to linear movement parallel with theshaft; a camand-follower connection between the weight- 'ed sleeve and shaft whereby linear movement of the weight in one direction is translated into rotative movement of the shaft in one dlrectlon and linear movement of the weight in the opposite direction produces the opposite rotative' effect; a pressure cylinder; a

. piston operatively associated with the weight and adapted to reciprocate axially of the cylinder, moving in one direction by fluid pressure against the weight and in the opposite direction by gravitation of the weight;

a pump; a pipe connecting the pump and cylinder, said pump being adapted to propel fluid to the cylinder againstthepiston under pressure; a check valve in the said pipe; a power means to actuate the, pump;

automatic means associated with said piston? and adapted to de-energize, the power means to terminate the fluid pr'essureactuated movement of the piston; a second automatic means responsive to a CODtIOlVGhlClQ to energize the power means upon the departure of the control vehicle;and means responsive to the control vehicle to reduce the flu d pressure against said piston-upon the approach of the control vehicle, thereby causing the gravitational movement of the piston.

' power means.

; 15. A signal system having, incombina tion: a pivotally mounted signal'member ;a substantially vertical revolvable' shaft operatively connected to the signal member; a I

weighted sleeve slidingly embracingthe shaft and adapted to reciprocate-thereon;"a guide; engaging the sleeveand adapted toconfine I tween the weighted sleeve and shaft whereby the sleeve tolinear movement parallel with the shaft; a cam-and-follower connectionbe 7 V with the weight and adapted toreciprocate-g axially of thecylinder, moving in one direc-;

tion by fluid pressure against the weight and in the oppositedirection by gravitation of the weight; afluidreservoir; a pump ;a pipe connecting the reservoir and pump; a pipe the reservoirtothe cylinder under-"pressure;

: a check valvein the second pipe; an el ectric qconnecting the pump andworking' cylinder, 7 said pump being adapted topropel fluid from '90 motoroperatively connected with the pump an automatic switch associated with the 'PiS-f ton, said switch'being adapted to de energize i the motor to terminate the fluid-pressureactuated movement of the piston; a return pipe connecting the cylinder and reservoir; a valve in the return pipe; a yielding meansnormally maintaining said Valvein a closed position; and electro-magnetic-means respo sive to a passlng VBlllClGtO open sald valvein causing thepiston to move downward under pressure from the weighted sleeve. i

opposition tothe yielding means, thereby reducing the'fluid-pressure in the cylinder and 16. A signal; system having,iin combina{ tion: a signal member; a vertical revolvable shaft; a floating sleeve embracing the shaft and operativelyconnected; to the signal mem- 1 i her, said sleeve havinga V-shaped camFsurface on its lower edge; a follower carried by the shaft, said follower-supporting the fioating sleeve and normally engagingthe sleeve at the vertex of the cam surface;-a member mounted axially slidable relative to the shaft;

cam means interconnecting said shaft and slidablemember whereby, vertical movement of said member will cause rotation of the shaft; power means to raisethe slidable member against gravity and thereby tor-cause rotation of thesha ftin onedirection, said slidable member being sufficiently weighted to cause rotationvof the shaft in the a opposite direction by its gravitationalfall and means responsive to a passing vehicle to control'the In Witness that I claim the foregoing I have hereunto subscribed my name this 4th day of February, 1931. i

1 I MERCER- DJ WILSON. 

